Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02210066 1997-07-10
WO 96t21923 PCTA~)G~ 1127
WIND l~'lK~ENT AND CLOSURE M~MR~ FOR WIND INSTRUMENT
The invention relates to a wind instrument, such as
a saxophone, clarinet, flute, bassoon, oboe or like
instrument provided with closure members.
Such a wind instrument comprises a basic body in
which extends at least one central duct which is bounded
by a peripheral wall of the basic body. Formed in the
peripheral wall is a number of holes which connect the
duct with the surrounding air. At least a number of these
openings can be opened and closed by means of closure
members mounted on the instrument. Particularly the pitch
which is produced is determined by the open or closed
position of the closure members during playing of the
instrument, wherein generally the higher the position of
the closure member which is opened, the higher the pitch
obtained.
In known wind instruments of this type the closure
members comprise in each case a cup-shaped holder which
forms part of the control means and wherein a closure pad
is fixed, for instance with sealing wax. This closure pad
constitutes the closur~ member which can close and leave
clear the associated opening in the peripheral wall.
According to the prior art the closure pad is for in-
stance composed of a felt cushion bounded by leather. In
some cases a basic layer of cardboard is also used as
well as a thin plate of metal or plastic riveted thereto.
For good operation of the wind instrument it is
essential that the closure members do indeed close prop-
erly in the closed positior.. E~en in the case of a minor
leakage the desired tone or tones cannot be produced, or
30 in any case not properly. Accurate arrangement of the
closure members is therefore of great importance. This is
~ particularly the case when a plurality of closure members
is closed simultaneously with common control means.
The closure pads must be replaced regularly due to
35 wear and/or deforming thereof. This is a time-consuming
and costly process. The closure pads are usually secured
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WO 96/21923 PCT/NL96/00027
in the cup-shaped holders with sealing wax and, when a
complete engagement in the closed position is not already
obtained initially, a precise adjustment of the closure
pads is subsequently obtained by arranging small fill-
ings, for instance of paper or cardboard, behind thecushions so that the closure members seal properly over
the whole periphery and/or so that the simultaneously
closing closure members are completely sealed.
The invention has for its object to provide a wind
instrument of the type stated in the preamble wherein
said drawbacks of known instruments occur to a lesser
degree.
According to the invention this is achieved by
applying the characterizing feature of claim 1. Due to
the plate of stifl material the closure member will
automatically make a good engagement on the whole periph-
ery of the opening when it is pressed against the open-
ing. Due to this engaging position of the closure member
coupled to the control means, the correct positior of the
closure member relative to the opening is achieved at
once. Due to the yieldable means the closing stroke and
the height of lift of the closure member of the one
opening can adapt yieldably, i.e. automatically, to the
closing stroke respectively height of lift of the closure
member of another opening, said two openings being con-
trolled simultaneously by means of common control means.
This prevents the one closure member leaking when the
other closure member which is coupled thereto is already
closed. By applying this inventive step the mutual ad-
justment of these mutually coupled closure member nolonger requires an extremely precise adjustment. Replace-
ment of closure members hereby becomes very simple.
Adjustment operations are no longer necessary, or hardly
so. The control mechanism is subjected to a lesser degree
of wear and the stop corks of the control mechanism are
trapped less frequently, resulting in a longer lifespan.
Particularly in a known saxophone wherein the clo-
sure members can have very large dimensions, the closure
pad has a marked influence on the sound in that it func-
tions as a muffling area. Particularly the high harmonic
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WO 96/21923 PCT/NI3'~D27
sounds in the produced tone are rapidly muffled hereby.
It has been ~ound that in the wind instrument according
to claim 2 the sound is considerably improved and in
particular comprises more of the higher harmonic tones.
By using the hard, preferably metal, plate material which
remains substantially uncovered, the above stated muf-
fling is avoided.
The closure members increase the amount of material,
the weight and the production activity involved in making
wind instruments. The invention provides a wind instru-
ment according to claim 3 which requires less material,
has a lower weight and is easier to manufacture.
A suitable embodiment is further characterized in
claim g. The foam material can effect precisely the
required yieldability of the connection over a small
height.
A further developed wind instrument is characterized
according to claim 5. The closure members are herein
connected to control rods by means of a simple support
member allowing a tilting movement.
By applying the step of claim 6 is achieved that a
couple sufficient to centre the closure member on the
opening is already realized with a small closure force.
Moreover, the closure member is then free on both its
sides and therefore muffled less.
The invention also relates to and provides a closure
member according to any of the claims 8-10.
The invention will be ~urther elucidated in the
following description with reference to the accompanying
drawings, wherein
Figure 1 shows a perspective view of a saxophone,
being a wind instrument according to the invention;
Figure 2 shows a detailed view of a closure member
of the saxophone of figure 1 as according to arrow II;
Figure 3 shows a cross-section of the closure member
of figure 2 at the position of the opening;
Figures 4, 5, 7-13, 15, 17-19, 21 and 23-28 each
show a view corresponding with figure 3, in each case of
a different embodiment;
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WO 96/21923 PCTINl~G~ 111127
Figure 6 is a perspective view of a fraction of an
instrument according to the invention;
Figure 9A is a perspective view of detail IX of
figure 9;
Figures 14 and 16 each show a fraction of the top
view of figure 13 respectively 15; and
Figure 22 shows a top view of the fraction of figure
21.
In the figure description functionally identical
elements have the same numerals.
The saxophone 1 shown in figure 1 comprises a basic
body or hull 2 of metal, for instance brass, through
which extends a duct. A hull of wood, hard plastic or
compound material, such as ground hardwood with epoxy
resin, is also possible in particular instruments.
This duct extends from the mouthpiece 3 to the
opening 4 on the front end of basic body 2. When the
saxophone 1 is played the column of air in the duct is
brought into resonance. The resonance frequency and thus
the pitch produced depends on the length of the resonat-
ing air column.
In the peripheral wall of basic body 2 is formed a
plurality of openings which can be closed or opened by
valves 5. The length of the resonance column is generally
determined by the valve opened closest to the mouthpiece
3.
The valves 5 comprise closure members which are
movable by control means 6 between an opened position at
a distance from the associated opening 4 and a closed
position wherein the opening 4 is closed by the closure
member 15. The valves 5 are controlled by hand in order
to create a desired pitch.
Figure 2 shows the principle of a valve 5 of the
saxophone 1. In this embodiment the valve 5 comprises a
cup-shaped cover 8 receiving a closure member 15 to be
described further. The cover 8 is connected to a rod 21
which is pivotally connected at 10 to a support 11 fixed-
ly connected to basic body 2. On the opposite end the rod
21 is provided with a key 9. On rod 21 is arranged a leaf
spring 12 which, in this example, urges rod 21 in coun-
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WO 96121923 PcT~ G~ c27
ter-clockwise direction, i.e. urges the cover 8 onto
opening 4. The cover 8 with closure member 15 received
therein can thus be moved away from opening 4 by pressing
the key 9. The opened position of valve 5 is determined
by a stop element 13 which is usually made of cork.
Figure 3 shows the embodiment of the valve 5 at the
position of the opening 4. The actual closure member 15
comprises a substantially stiff plate 16, in any case a
plate of hard material, which is provided with sealing
material 17 on the side facing toward the opening ~. In
this embodiment the sealing material consists of a ring
18 either of foam material, such as a thin layer or
cellular rubber with a thickness in the order of magni-
tude of 0.5 to 2 mm, preferably between 0.5 and 1.5 mm
and in particular between 0.7 and 1.2 mm, which layer is
optionally covered with a thin layer of supple leather
19, or of very soft solid rubber which is for instance
vulcanized to the plate 16, said ring being connec~ed
directly to the stiff plate 16. The edge 20 around the
opening 4 is usually made flat so that the surface of the
sealing material can make good sealing engagement on this
edge. The leather layer 19 is preferably not used and the
thin layer of cellular rubber consists of cellular rubber
with very small closed cells. The average cell diameter
is smaller thar 0.5 mm, for instance smaller than 0.3 mm
and preferably smaller than 0.2 mm. This sealing material
is for instance coated on the outside with a sealing film
to prevent infiltration of moisture. In small valves, for
instance of a clarinet, the said ring 18 is for instance
replaced by a round disc of the same material.
The hard plate 16 is preferably a metal plate made
flat so that it extends accurately at a constan~ d-stance
from the edge 20 and the sealing surface ls thus support-
ed accurately in one and the same surface. The plate 16
has a rigidity, depending on the selected metal tv~e and
~ the diameter of the tone opening, such that the de_lec-
tion of the plate resulting from strong playing fo~ce
(approximately 2N) is preferably smaller than 0.3 mm,
more preferably smaller than 0.2 mm, for instance n the
order of magnitude of 0.1 m~. In the case of stainless
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WO 96/21923 PCT/NL96/00027
steel (stainless steel 430) the plate thicknesses are 0.1
to 1 mm, preferably 0.15-0.8 mm, most preferably in the
order of magnitude of 0. 5 mm.
In the shown preferred embodiment the closure member - ,
5 15 is yieldably connected to the control means 6. This
yieldable connection is realized in that a male part 23
of a hard rubber press fastener is glued into the cover 8
with interposing of a foam resin pad 22, preferably with
a thickness in the order of magnitude of 2 mm. The stiff
plate 15 is pushed over this male part 23 of the press
fastener and the female part 24 (of hard rubber or plas-
tic) of the press fastener is subsequently snapped onto
the part protruding through the plate 16. The foam mate-
rial 22 constitutes yieldable means with which the clo-
15 sure member 15 is connected for slight movement to thecontrol means 6. In terms of its position, the closure
member 15 and particularly the sealing ring thereof can
adapt precisely ~o the edge 20 and make all-round close
sealing engagement therewith, even if in the not yet
2 0 fully closed position the closure member 15 were to lie
in slightly inclining position relative to the edge 20.
Due to the pressure force of the spring 12 or, in the
opposite case, due to the pressure force exerted by hand,
the closure member 15 comes to lie precisely on the edge
25 20. Due to these yieldable means in the form of the layer
of foam material 22, the valves 5, mutually connected for
instance as according to figure 6, are easily adjustable
relative to each other. With little adjustability the
simultaneous good closure can be realized with little
pressure force. In figure 6 for instance the valve 5B is
also closed each time that each or any of a series of
valves 5A iS closed. For this purpose the rod 21B which
is urged to the open position by a spring 12B is fixedly
connected to a longitudinal rod 38, which supports via a
3S cork 41A on the rods 21A which themselves support in the
open valve position on the body 2 via a cork 42A. If at
least one of the valves 5A is closed by means of the
finger key 43 soldered thereon, the closure members 15B
and 15A will simultaneously close properly, because both
closure members 15B and 15A are connected to the control
CA 02210066 1997-07-10
WO 96121923 PCT/NL96/00027
means 6 via the yieldable means. It is also conceivable
that a valve 5B can be closed either individually and
directly by means of its own ~inger key (not drawn), or
together with one or more other valves 5A by means of
longitudinal rod 38.
Figure 4 shows a slightly modified embodiment. The
cover 8 is herein omitted and the closure member 15 is
directly connected to the rod 21 of control means 6 using
the above described press fastener connection. The mass
of the control means 6 hereby becomes smaller, whlch can
contribute to a lighter operation of the valve mechanism.
In the embodiment of figure 5 a snap connection by
means of a p-ress fastener is likewise used. The male part
30 of the press fastener is arranged fixedly in the cover
8 by means of a glue or cement connection 31. A ring 32
of yieldable material, in particular foam material, is
first arranged o~er the protruding portion 34 of the male
press fastener part 30, whereafter the metal closure
plate 15, a second ring 36 of yieldable material and the
female part 24 of the press fastener are successively
arranged. For a permanent connection the press fastener
part 30 can for instance also be soldered to the rod 21
of the control means 6.
As can be clearly seen in the figures 3-5, by far
the greater part of the opening 4 is closed by the uncov-
ered surface of the stiff metal, for instance brass plate
16, which has on neither of its sides any centrally
located engaging material causing muffling. Little or no
muffling hereby occurs at the position of the closed
opening 4, whereby the sound of wind instrument 1 becomes
fuller and more brilliant than is achieved with the usual
closure pads.
Fitting of the stiff plates 16 is very simple.
Hardly any or no adjusting operations are required to
ensure that the sealing material 18 engages the wnole
periphery of the opening 4.
It has been found that the tuning of the instrument,
which is also determined by the distance of the closure
members 15 to the opening 4 in the opened position, can
be controlled better. The mechanism is found in practice
CA 02210066 1997-07-10
WO 96/21923 PCT/NIg6/00027
to be a little faster and the sticking (running on) of
valves does not occur or does so to a lesser degree.
The invention is not limited to the preferred em-
bodiment's shown in the figures. Even without the yield-
able connection of the closure member 15 with the controlmeans 6 the advantage is already achieved of simpler
mounting of the closure plates with less adjustment work
and/or a better sound of the instrument.
Assembly of the closure members 15 using the snap
connection, particularly formed by a press fastener,
enables a very simple replacement of the closure member
15. However, it falls within the scope of the invention
to fix the closure members 15 to the control means re-
spectively in the cover 8 with for instance a piece of
double-sided foam adhesive tape.
According to figure 8 a smooth pin 39 is fixed to
the control means 6, for instance by soldering. The ring
32 and the closure member 15 are placed on the pin 39 and
held thereon by means of an element, for instance a piece
of folded rubber hose 40, which clamps on the protruding
end of the pin 39.
In figure 6 the closure member 15A, 15B is fixed to
a cover 8 by a base plate 45 of a pin 39 being soldered
to the cover 8 and a rubber block 25 being placed over
this pin 39 and glued to base plate 25 and stiff plate
16. The plate 16 is centred by the pin 39 and can move
slightly axially as well as tilt relative to the cover 8.
Rough mutual valve adjustment takes place by slight
bending of brass rods 21 or of other control elements of
the control means 6.
The valve 5 of figure 7 is the same as that of
figure 6, with the modification that a filling 44 is
arranged between cover 8 and base plate 45 of a hard
rubber pin, so that universal rubber blocks 25 can be
employed for diverse distances s at different valve
dimensions.
The valve 5 of figure 9 comprises a cover 8 which is
welded to a rod 21 and in which a base plate 45 of a pin
39 is rigidly connected via a filling 44. A flexible,
substantially non-stretchable, thin membrane 46 is first
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WO 96/21923 PCT/NL9'~10027
adhered to a ring 32 of elastlc material, for instance
0.5 to 1 mm cellular rubber. Placed thereon is a stiff
pressure ring 47 and on the latter a small, practically
solid perforated rubber block 48, for instance a ring
with a thickness of 0.5-1 mm, which are all placed onto
the pin 39 above the stiff plate 16. The peripheral edge
of the membrane 46 is subsequently glued in stretched
position to the stiff plate 16. The base plate 45 is then
rigidly glued to the cover 8 via filling 44. The stiff
plate 16 can swivel slightly about the ring 48 and can
displace slightly in axial direction due to the yieldable
layer 32. The sealing ring 18 of cellular rubber may
therefore be thin, for instance 1 to 2 mm.
The valve 5 of figure 10 has said membrane 46 and
the rubber block a3 which replaces the ring 32. The
elasticity of the rubber block 49 is in the order or
magnitude of 0-70~ Shore, preferably 30-50~ Shore, i.e.
chosen such that the required yield of O.25 to O.5 ~m is
automatically obtained with finger force actuation of the
keys to ensure the closed position of mutually coupled
valves 5. The block 49 is glued to the stiff plate 16 and
base plate 45. The membrane 46 is glued to the base plate
45 and stiff plate 16. The membrane 46 of figures 9 and
10 has in reality a slight inclination.
In contrast to figure 10 the centering membrare 46
is replaced in figure 11 by the centering press fastener
23, 24 of hard rubber or plastic.
In figure 12 the centering of the plate 16 is real-
ized almost solely by means of the membrane 46 which is
glued between elastic rubber block 49 and cover 8 and
glued to the plate 16. This is a simple and effective
valve construction. The block 49 supports unglued against
plate 16 such that plate 16 may swivel somewhat. Block 49
can have a half ball-shaped lower end or be constituted
wholly by an elastic ball.
The valve 15 of figures 13 and 14 does not have the
cover 8. A brass bush 50 is soldered to rod 21 and has a
threaded hole 51 into which is screwed a screwed rod 52
with a grooved head 53 for a screwdriver and a lower
piece 55 comprising a threaded hole 54. A stiff, concave
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WO 96/21923 PCT/NI96/00027
or flat plate 16 of 0.4 mm brass is screwed into the
threaded hole 54 by means of a screw 56 with a stop edge
57 with interposing of an elastic rubber block 49. Sol-
dered to the plate 16 is an ornamental disc 58 of thin
brass and a central opening 59 thereof is optionally
covered with a soldered brass ring 60. A small play K of
for instance 1 or 2 mm is left free between bush 50 and
ring 60. Due to the yieldable means formed by the elastic
rubber block this closure member 15 can yield slightly
after closing of the valve 5 during a small continuing
downward movement of bush 50. This closure member 15 is
easily adjustable when the counter-nut 61 is released.
The valve 5 of figures 15 and 16 has a brass bush 62
welded to a rod 21, in which bush a hard rubber base
plate 45 is glued, optionally with interposing of a hard
filling piece 44. A concave, stiff brass plate 16 enclos-
es a rubber block 49 and is itself enclosed by a soft
ring and a female part 24 of a press fastener.
In all figures the yieldable means 6, for instance
consisting of a layer 22 or 32 or a block 49, allow a
small stroke of the closure member 15 at a normal finger
keying force during playing of the instrument such that
the good sealing closure of each valve 5 of a plurality
of simultaneously closing valves 5 is obtained when there
is sufficient stiffness of the valve control. Too soft an
elasticity is disastrous. While playing the instrument
the musician must retain the feeling of a direct touch.
The stroke permitted by the yieldable means 6 is prefera-
bly less than 3 mm and more preferably less than 1 mm. A
stroke in the order of magnitude of 0.5 mm is ideal. The
more a sensitive, for instance professional musician
appreciates the perfect feeling of contact with the
instrument the smaller the stroke is chosen, for instance
0.2-0.4 mm, since in such a case somewhat longer adjust-
ment work and ~elated higher costs are less important.However, the adjustment of a known instrument intended
for professional use requires much more time.
In the case the, particularly professional, musician
appreciates the absolute reliability of the perfect
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WO 96/21923 PCT/NLgG~ 7
11
closure of the valves 5, he will prefer a slightly longer
stroke, for instance 0.4-0.7 mm.
For amateurs who prefer preventing possible valve
correction, a stroke in the order of magnitude of l mm
and more is preferable.
Understood by the said finger force is a playlng
finger keying force, i.e. a kinetic energy corresponding
with a static force lying between 0.25 and 5 N, particu-
larly between 0.25 and 3 N and preferably smaller than 1
N.
Figure 18 shows on a scale of 6:1 a convex closure
member 15 consisting of a metal, for instance tombac,
stiff plate with a sealing ring 18 of cellular rubber,
which closure member 15 adapts if necessary to the edge
20 by swiveling slightly in that it is received for
slight swiveling in a solid rubber ring 71 with U-shaped
profile and having a hardness between 40~ and 80~ Shore.
The valve holder 8, indicated with dashed lines,
which is used in known wind lnstruments is omitted and to
an arm 21 of the valve control mechanism is soldered a
bolt head 72 and therearound a tombac ring 73. Around the
bolt stem a ring of cellular rubber is arranged between
two rings 73 which, together with the ring 71 and the
closure member 15 contained therein, are clamped together
by means of nut 75 screwed onto the bolt stem 74. The
wind instrument of which all closure members 15, irre-
spective of their diameter, are practically all provided
with identically dimensioned connecting means 71-75 and
which have sealing rings 18 with a thickness of 0.5-1 mm
and a width of + 3-8 mm, has a beautiful sound and re-
quires hardly any adjustment after assembly. The sealing
is ensured, the instrument plays smoothly, easily and
clearly.
Figure 19 is identical to figure 18, with the dif-
ference that a rubber hose 77 is arranged round the boltstem 74 and the closure member 15 is further enclosed by
means of a ring 78 of soft, practically solid rubber with
a hardness in the order of magnitude of 0-50~ Shore.
According to figure 20 the closure member 15 is
fixed to the arm 21 in that the bolt shaft 74 with bolt
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WO 96/21923 PCT~"~OG27
12
head 72 and ring 73 together with a U-shaped brace 80
form a mutually soldered unit 81, to which the closure
member 15 according to figures 18 and 19 is fixed. This
unit 81 iS placed on the arm 21 as according to arrow 82
and clamped thereon by means of screw 83.
In figures 21 and 22 the closure member 15 is fixed
to a round disc-shaped end 84 of arm 21 by means of a nut
75, a practically solid rubber ring 71, a metal ring 73
and a cellular rubber ring 32 and by means of a bolt stem
end 85 soldered in said end 84.
Figure 23 iS identical to figure 21, with the dif-
ference that the closure member 15 with its practically
solid rubber ring of for instance 40~ Shore is clamped
directly against the disc 84. If the ring 71 fits closely
round the bolt stem 74 the nut 75 may optionally be
omitted.
In figures 18-25 the components are shown wi-h their
preferred dimensioning. Reference is made to said indi-
cated dimensions. Dimensions in the same order of magni-
tude are preferably applied. The diameters and the rings18 of the various closure members 15 are of course adapt-
ed to the openings 4 of the basic body 2. Identical
elements are otherwise used for the connections.
Because the closure members 15 seal so well, the
25 valve springs of closed valves can be ad~usted with less
tension.
The edges 20 of the openings 4 are each properly
ground flat in one and the same plane.
In figures 24-28 a completely flat, thin metal plate
16, for instance of titanium with a thickness of for
instance 0. 2-0. 5 mm, preferably of this order of magni-
tude, fits on the flat edge 20 with interposing c- the
thin sealing ring 18 of cellular rubber with closed cell
structure of for instance a thickness of 0. 5-2 mm, pref-
erably of this order of magnitude. A plate 16 of ~lasticor other form-retaining, albeit elastic, material can
also be envisaged. The plate 16 is adhered centrally to
the rod 21 with interposing of yieldable means 22, which
in figure 29 consist of a soft rubber core 92 (hardness
40 40-80~ Shore) with a diameter of 2-7 mm and a height of
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WO 96/21923 PCT/Nh9G~ 27
13
1-5 mm, which is surrounded by a ring 93 of cellular
rubber with a diameter of 4-12 mm and a thickness of 1-5
mm. Ring 93 is glued on both sides between the plate 16
and a bush 94 which is soldered to a rod 21 without cover
5 8 or glued between the plate 16 and a cover 8 normally
integrated with the rod 21. The ring 93 serves to in-
crease the adhesion surface of the layers of glue 96
without preventing the required swivel possibility of
plate 16. The core 92 is loosely enclosed between bush 94
10 (or cover 8) and plate 16 or is glued to only one side,
and can be conical or have another shape.
The plate 16 is preferably completely flat, but can
however be permanently concave or convex under the influ-
ence of the closing force. The yieldable means 22 can
lS also take the form of the elements 49 of figure 12,
preferably having a thin middle portion.
All given dimensions and values serve as example and
indication of the order of magnitude. The springs which
tension the control means are adapted to the necessary
20 compressions for closing the valves, i.e. tensioned
considerably less than usual. The instrument according to
the invention hereby plays very lightly. It is less
tiring and it is possible to play faster and better. The
tension of the springs of valves closed in rest position
25 is preferably low such that as a result of hard blowing
these valves are only just not blown open by the then
occurring air pressure; the tension of the springs of
valves opened in rest position is preferably low such
that these valves move up and downward with just enough
30 speed to follow the fingers during fast playing. The
spring tensions are herein chosen slightly higher for
safety reasons.
In figure 24 the displacement of the valve 15 in
radial direction is prevented by the edge of the Dush 94
35 which extends up to a small d stance of for instarce 1 mm
- from the plate 16.
In figures 25-28 a guide ring 97 is glued on plate
16 and on the sealing ring 18 extending outward of plate
16. The guide ring ~7 of elastic material, for instance
40 foam plastic with a thickness of 0.7-2 mm, preferably
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14
0.7-1.5 mm, is preferably a little stiffer than sealing
ring 18 and substantially holds valve 18 in position in
radial direction. The rotation of valve 15 is prevented
as in the other figures by the ring 93 of soft cellular
rubber which is glued on either side by means of a glue
layer 96. The glue layer 96 cannot prevent swiveling of
the core 92 or is absent at the core 92. A ball-shaped
core 92 as according to figure 26 preferably enhances the
swivel possibility of valve 15. The ball-shaped core 92
is for instance of solid rubber or teflon with hardness
in the order of magnitude of 40 or 80~ Shore at a diame-
ter of 1.5-5 mm. The tough core ensures a good finger
sensitivity requiring a small springing movement OL the
finger in the case of a force of + 0.25 N during soft
playing. At 2 to 2.5 N in the case of fast and forte
playing the springing displacement at the position of the
finger keys should not be too great, (order of magnitude
of 0.5-1.5 mm). The springing displacement is the sum of:
0-0.5 mm com~ression of the sealing ring 18 at a
layer thickness of 0.8-1.25 mm of cellular rubber;
0-0.25 mm bending of the plate 16 of stainless
hardened steel with a thickness of 0.4 mm or titanium
which may even be a little thinner, in any case a plate
16 with a stiffness in this order of magnitude;
a small springing displacement of the core 92 in the
order of magnitude of 0-0.75 mm;
and a small springing displacement of the control
system in the case of a plurality of mutually coupled
valves.
The valve 15 can be supplied separately as mounting
of repair valve, wherein the technician measures the
internal height t of the cover 8 if this is unknown to
him and selects a ring 93 and a core 92 of roughly the
same dimension _. The rings 93 are preferably provided on
both sides with self-adhesive layers which are covered
with removable pull-off strips.
According to figures 26 and 27 a thin resonance
plate 98 is fixed centrally to plate 16 via a central
thin layer 99 of cellular rubber or is directly glued
onto sealing ring 18. The diameter of the resonance plate
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WO 96/21923 PCT/~ 27
98 is 2-4 mm smaller than the opening 4 and is for in-
stance mounted as according to figure 27 by means of a
spoon lOo which is held against the edge 20 with a stop
101 while said spoon is held by its handle 102. Glued to
spoon 100 is a magnet 103 which attracts the steel reso-
nance plate 98 having already glued thereon the layer 99
which carries an adhesive layer on the upper side. The
resonance plate 98 is shifted over the magnet 103 to a
centred position relative to opening 4, whereafter valve
10 15 is moved to opening 4 to be fixed to the resonance
plate 98. The spoon with magnet is then removed.
The above mentioned sealing ring 18 of cellular
rubber with closed cells can be used to addltional advan-
tage in a bass clarinet and like instruments to avoid the
15 problem of "blowing bubbles".
The valve 15 of figure 17 has a frustoconical ring
93 of cellular rubber glued to plate 16 and glued in bush
94 with frustoconical guide edge. Plate 16 can swivel on
the rounded lower end of core 92 of solid rubber or
20 teflon, each of 40~-80~ Shore.
Figure 28 shows a detail of a wooden musical instru-
ment, for instance a clarinet, of which the opening 4 is
bounded by a concave valve seat edge 20. The valve 15 is
constructed in principle as in figure 26.
In order to obtain the required flexibility of the
tilting movement of plate 16, the diameter of the foam
rubber rings 22 is between 4 and 15 mm, preferably be-
tween 5 and 13 mm and more preferably between 7 and 11
mm. The internal diameter of said bush 94 (if present) is
slightly (+ 1 mm) greater than the outer diameter of ring
22.
The plates 16 are produced in flat condition by
cutting them from flat plates by means of laser beams or
by an etching operation in which metal material is re-
moved at the cutting lines, for instance from both sides,during corrosion by means of an acid. According to known
etching techniques the cutting lines are determined by
light-sensitive films on one or both sides of the metal
plates, which films are treated with light according to a
predetermined pattern.
